Lawn & Garden Education

How to Prune; The where, why & when

Generally speaking, the excitement and rejuvenation of spring often brings with it some daunting tasks you may not feel qualified to tackle. If you are anything like me, the thought of pruning usually carries with it visions of mangled plant life and good intentions gone bad. Having said that, it needn’t be so confusing. With a little information and the right tools you too can master this all-important garden project.

We’ve assembled for you a primer on “why” you should feel motivated to get pruning, and more importantly, “how”.

The principal reasons for pruning are:

To produce more or better blooms and/or fruits

To develop or maintain a desired size or appearance

To re-establish a balance between root and branch systems after transplanting

To train a young plant

To rejuvenate, older, neglected shrubs

To maintain health

To repair injury

Buy the best tool you can afford. Quality tools, properly cared for, will last many years and do a far better job than cheaply made ones (and your hands will thank you!). Your job will be easier and your plants will benefit for it. Never tackle a branch that is too big for the tool or you’ll damage both the tool and the plant. When in doubt, reach for a larger tool.

Your entire backyard pruning can be done with just three or four single hand tools:

There are two styles of hand shears. Scissor or hook-and-blade shears are considered by many to be the best. They make the cleanest and closest cut. Anvil shears have a straight-edged blade that cuts against a soft metal anvil.

Hedge shears have straight blades at least 8 inches long and are designed to clip soft young growth.

Above all, make sure to keep your pruning tools sharp. Regularly sharpen blades with a file designed for sharpening, not a stone, and be sure to maintain the original angle of bevel on the blade.

After each use, clean your tools and wipe them down with an oily cloth. Once or twice a year, rub linseed oil into wooden handles. Use kerosene or another solvent to remove sap from tools. Have saw blades sharpened professionally.

Pruning Methods

Before you set out to prune, learn how plants grow. Trees and shrubs put on new growth each year from the ends of the branches (terminal buds) and from side branches (lateral buds). A plant’s direction and rate of growth are determined by its terminal buds.

Lateral buds form branches and twigs that fill in the skeleton of major branches.

Dormant buds, which are much less obvious and sometimes hidden below the bark, held in reserve. They only begin to grow if the plant suffers injury to its terminal and lateral buds.

A key to skillful pruning is learning how to take advantage of lateral and dormant buds in redirecting growth or rejuvenating a plant.

Pruning is the removal of older twigs and branches that have begun to harden and become woody. Unlike shearing, which is done during the growing season, pruning is usually done during the late fall or winter, and some instances the early spring before bud break.

The cardinal rule is to prune back to a branch or a bud, or you will leave a stub that will die back and cause decay and disease. Make pruning cuts no more than 1/4-inch above a bud or side branch.

Shearing

When you shear a hedge, you are removing all of its new terminal buds, thereby encouraging vigorous lateral growth for a dense, bushy hedge.

At the same time, you’re keeping the hedge from growing too high. Shearing is usually restricted to removing soft, first-year growth that is easy to cut.

It is best to shear shortly after new growth begins in spring so that the lateral buds will have all season to grow and make the hedge bushy.

If you make the common mistake of waiting until the end of the growing season, your hedge will not get bushy. You’ll also end up with unsightly brown tips, because no new growth will cover them.

When To Prune

The time to prune greatly depends on the kind of plant you have. The kind of plant will tell you whether to prune in late winter, spring, early summer, late summer, or fall.

Late Winter

This is the best time to prune many plants, including fruit trees, certain roses, broad-leafed evergreens, vines, and some flowering plants.

Drastic pruning of a neglected plant in late winter can cause overly vigorous growth of leaves and wood at the expense of flowers and fruit. Either postpone such pruning until spring or spread it out over several seasons.

Spring

Remove any wood damaged by winter wind, ice, or snow. Remember, prune back to a healthy bud or limb. Repair damage from animals.

Early Summer

Time to shear evergreens and hedges. This is when they are putting on their greatest growth. This is also the time to prune all early-blooming shrubs after the last flowers fade.

Late Summer

This is a good time to prune certain shade trees, such as maples and birches, that lose too much sap if pruned in spring.

Fall

In all but the most northern regions, this is a good time to prune roses, clematis, hydrangea, buddleia, crape myrtle, potentilla, hibiscus, grape vines, and the mall-berry fruits.

Pruning Mature Trees

Mature trees that have been pruned since planting require little besides maintenance care: removal of dead or damaged wood or the occasional general thinning to allow more air into the crown.

Always cut large limbs back to a live branch or the main trunk. Most branches have an obvious, sometimes wrinkled, swelling at their base. Make your final cut just outside this collar.

Use the tree-cut method when sawing off a large branch. First make an undercut at least 6 inches from the bark collar.

Then, about an inch beyond that, remove the limb with a top cut.

Finally, remove the remaining stub with one smooth cut from top to bottom just outside the bark collar. With a very big limb, first reduce its length by removing it in sections.

Pruning Ornamental Trees

In the first year, while the plant is dormant, remove weak or unruly shoots, crossing branches, and suckers.

In the spring of the second or third year, remove poorly spaced branches. Thereafter, leave the plant alone, pruning only for dead, diseased, or damaged wood or to correct a poor shape.

Train flowering trees as trees rather than large shrubs; with a central leader. Cut off all suckers that sprout from their roots.

The best time to prune most flowering trees is just after the blossoms fade unless you want to leave attractive berries,on which case prune in late winter.

Before pruning a flowering shrub, check to see whether it flowers on wood produced the same year or on year-old wood that grew during the previous season.

Most shrubs have already bloomed by June.

If flowers form on old wood

The shrub should be pruned immediately after the flowers fade. If you prune these plants in winter or spring, you’ll cut away flower buds. If you don’t prune them immediately after they flower, they won’t have enough time to develop a new set of buds to flower the following spring.

If flowers are produced on new wood

The shrub may be pruned in late winter or early spring before the buds become green.

Shrubs that flower on old wood should be pruned in the following manner.

Cut back shoots that have borne flowers, leaving vigorous young shoots lower down on the main stems. Remove any puny or overly vigorous shoots and suckers that spoil the shape of the plant.

On shrubs three or more years old, begin to remove some of the oldest shoots at the base as close to the ground as possible, to simulate the growth of new shoots. Remove one out of every three to five older shoots depending on the size of the shrub.

Shrubs that flower on new wood should be allowed to form a strong framework of branches in their first several years.

In the first year, tip back shoots to the first strong bud or pair of buds. Remove puny, overly vigorous shoots.

In the second year and there after prune back new shoots to within one or two buds of last year’s growth. In the fourth or fifth year begin to remove older branches at the base.

REMEMBER

Remember, pruning old shrubs, as we have shown you thus far, is easy and tempting to do more, but it is always good to know the original form and maintain the shrub that way.

Prune annually to maintain your trees and shrubs.

If major pruning must be done, do the pruning in stages. One portion of shrub one year, and take care of the rest the next year.

If a shrub’s growth has become thin and floppy, cut back all the leggy stems by half and remove some of the oldest stems to the ground.

If a shrub has become too twiggy, with many small branches at the ends of the branches, prune the oldest branches to the ground and cut off the outer twiggy growth.

In all of the above instances a healthy and reasonably vigorous plant will come back with lush growth and fill out within three years.

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